s1_generate_a_series_of_files(){
   for i in {1..100};do echo $i>/tmp/new_file$i;done
}
s2_list_4_files_in_long_format_about_account_and_group(){
   ls -l /etc/{passwd,shadow,group,gshadow} |sort -d
}
s3_find_items_related_to_given_username(){
   grep -h $1 /etc/{passwd,shadow} |sort -d 
}
s4_find_relate_to_given_group_name(){
   grep -h $1 /etc/{group,gshadow} |sort -d
}
s5_create_groups_for_given_group_names(){
   groupadd rnd && groupadd itoperation
}
s6_create_users_and_set_their_group_as_required(){
   useradd -G rnd adam && useradd -G rnd bob && useradd -G itoperation calvin && useradd -G itoperation david && useradd -G rnd edward
}
s7_change_users_shell(){
   usermod -s /usr/bin/sh adam && usermod -s /usr/bin/sh edward
}
s8_set_password_change_policy(){
   passwd -n 10 -x 60 -w 10 adam
   passwd -n 10 -x 60 -w 10 bob
   passwd -n 10 -x 60 -w 10 david
   passwd -n 10 -x 60 -w 10 calvin
   passwd -n 10 -x 60 -w 10 edward
}
s10_lock_bobs_password(){
   usermod -L bob
}
s11_include_adam_into_wheel_group(){
  usermod -aG wheel adam
}
s12_change_files_permission(){
  for i  in {1..33}; do
   chmod -R 640 /tmp/new_file$[3*i]; done
}

